The use of various polymerizable resinous materials is becoming more and more frequent in the dental profession. Such resinous materials are used as pit and fissure sealants to coat the biting surfaces of molars, as sealants to seal the surface of a cavity prior to filling with the dental restorative material, adhesives for orthodontic brackets, crowns, bridges, and the like, and as composites used as dental filling material. In applying these materials, it is desirable to dispense small quantities of the resinous material in a precise location and in precise quantities. This invention is directed to the provision of an instrument that is very useful for accurately dispensing predetermined quantities of paste-like or fluid materials such as dental resins.